The present invention relates to handling of longitudinally zippered film, such as may be used for making bags or packages, but not limited to such use, from a spirally wound spool to a constant point of infeed.
Commonly endless supply of longitudinally zipper film is spirally wound on a supply spool in order to avoid as nearly as practicable overlapping build up of the substantially greater mass zipper. On the other hand, at the point of use, it is necessary to deliver the film with the zipper at a constant point of infeed. Heretofore this problem has generally been met by mounting the supply spool on an oscillating stand controlled to effect the desired infeed. However, such oscillating stands require elaborate operating and tracking mechanism.